1. Field of the Invention
The present invention relates generally to a communication system and a transmission/reception method thereof, and in particular, to a communication system using a frequency overlay scheme (“frequency overlay communication system”) and a transmission/reception method thereof.
2. Description of the Related Art
With the development of communication systems, the types of services provided are diversified, raising the need for a broadband communication system supporting broadband service. However, due to the limited frequency resources, there is a limitation on the available frequency band even for the broadband communication system. In addition, because backward compatibility with the previously installed communication systems should also be taken into consideration, the system design is in difficulties.
The current broadband communication systems were designed on the basic premise that they are separately allocated different frequency bands to provide the broadband service in their service areas. However, the increasing demand for the frequency bands for the broadband service increases the license cost for the frequency bands, making it impossible to use the various available schemes proposed to provide the broadband service.
As a result, there is a need for a scheme for efficiently providing the broadband service while overcoming the limitation on the frequency bands, i.e., while solving the high license cost problem for the frequency bands.